Now that I have more experience flying the TU206G I wanted to update this thread for the benefit of those who might be researching this topic.

Takeoff performance is excellent with the TSIO-520M. I had shared some spreadsheets where I broke down the power differences between the TSIO-520 and the IO-550, but there is one significant factor that was not accounted for in those calcs - usable HP. The single largest limiting factor, in my situation, is cooling. The TSIO-520 may have more power on paper at altitude, but loaded down you're climbing at 300fpm above 8000ft to keep the temps down, I'd be REALLY curious to fly a 550 equipped 206 and experience the difference.

That said, if you run ROP, the 206H POH is a handy reference because the fuel flows are VERY similar if you're trying to keep the CHTs under 400* ROP. The book values for the turbo G model are not usable, as they allow for MUCH higher CHTs, whereas modern wisdom indicates 380* is a practical limit. That said, at least for cylinder 5, I have to accept 390* otherwise power settings are simply too low to be practical.

Thanks for the update, when you started this thread, I applied while I had a normally aspirated at 520, I now I have the IO 550 with a Voyager prop and Power Flow exhaust.

My home airport is at 7000 feet so I am almost always flying above 8000 feet, cruise climb for me is probably about 5 to 700 feet per minute, to keep the number five cylinder below 380 degrees.

What I value most about this engine is being able to cruise LOP, usually a little under 12 gallons per hour gets me 130 knots true, at around 10 or 11,000 feet AGL .

When tariffs pushed coffee prices up through the roof and supply dwindled, I ended up making many round trips from Flagstaff to the Los Angeles area to get 1000 pounds plus of premium green (beans) and bring back. I loved that I could fill the 80 gallon tanks, and make the round-trip, including climbing from 1500 feet to 11,500 right below full gross, and arrive at Flagstaff, with an hour left in the tanks! … I don’t know that I could’ve done that with another engine without an additional fuel stop. … although man I would have loved the extra speed from a turbo.

AZ Flyer wrote:My home airport is at 7000 feet so I am almost always flying above 8000 feet, cruise climb for me is probably about 5 to 700 feet per minute, to keep the number five cylinder below 380 degrees.

Sounds like a fantastic upgrade, is that 500-700 fpm climb at gross?

Late to the thread, but in case you haven't bought a 206 yet:

I owned a T210 with a TSIO-520-R for a few years and almost a full TBO run. No experience with a 550, but I'd recommend you give it a good look. The TSIO is just a pain in the ass, and real-world critical altitude almost never meets book. That's for the -R, with a 36.5" redline. C and -H engines are 32" so their turbos work less hard, but I'd still probably go for a 550. Even in a 210, where I often flew in the mid-teens.

.. I have flown both turbo and nonturbo 206’s a bunch . Turbo good when someone else buying the fuel. I’ve got a 550 in my 206 now . I like the 550 better overall . Seems more versatile to me.Home airport is 6k.

I sold my A185F of 20 years last July. Next Wednesday I'll put eyes on a 206 that I've signed a sales agreement and put a deposit on. IF all goes well it'll be flown to its new home over next weekend. 7 months without an airplane was much longer than I wanted to go through. Wish me luck, same to you too.

I had a gap between owning my 182 and my current 206. It's rough! Good luck! The 206 is a great machine.